Hart, 25, has been branded as one of the top goalkeepers in the world following his performances for club and country this season - a statement that Dudek has refused to dismiss.
"Hart has great potential for sure. He very quickly confirmed his ability in the Manchester City team. English fans complained recently about players in this position," he told Sky Sports News.
"But England have had some great keepers and Hart is another one on this list. He is going in the right direction. Can we name him the best in the world? It is a difficult question.
"You can find fantastic keepers in other leagues as well, for example [Iker] Casillas in Spain or [Gianluigi] Buffon in Serie A. They have kept their top form for a very long period. If Hart can do the same, he will have a real chance of becoming the best in the world."
Dudek also played for Real Madrid.